Cam someone recommend a couple good manga for me? ive read alot and i prefer a romance/harem manga, also school life romance/harem based manga. However I also like action manga and adventure manga as well as the fantasy genre. here is a small list of some I have read. Please quote me so I know you replied to me :)Thank you

I'm looking for some good horror mangas. I've just started reading mangas so i'm a newb. I've read Fort of Apocalypse but i just don't know where else to go from there....i'll take any suggestions.

Well I don't know I this is what you're looking for but why don't you try Arisa

Genre:Drama, Mystery, Psychological, Romance, School Life, Shoujo

For years the rash tomboyish Tsubasa had communicated with her twin through letters. She had formed the idea that the gentle Arisa led a joyful school life. But upon Arisa's sudden suicide attempt, Tsubasa vows to find the reason behind her twin's actions by taking her place at school. But will this supposed joyful life be too much for Tsubasa to handle? What does it have to do with the people disappearing from Arisa's school...

My favourite manga series are One Piece, HUNTER x HUNTER & FMA (currently on volume 18). Can you recommend me another series like those?

Just so you know I'm also currently reading Naruto and not really interested in Bleach at the moment, so I decided to save that for later.
I want to start something adventurous, with great characters, a large vibrant world & an enjoyable story.

I've constantly been hearing great stuff about Toriko since early 2013. I know the anime got canned, but how's the manga?

As far as I can see, you don't have Recca no Honoo (Flame of Recca), Yu Yu Hakusho (personally I've only watched the anime, but it was pretty good ;D), Elemental Gelade, or Immortal Rain.
The last 2 don't exactly fit the shounen category as most people think of it, but they're worth a read, ESPECIALLY Immortal Rain.

You also list a couple of shoujo manga, and out of the ones you listed, I would also suggest Shinobi Life, Superior, and Absolute Witch (a manhwa).